The present invention is generally related to optical fiber circuits and, more particularly, is related to an apparatus and method for making optical fiber circuits.
Advances in light wave technology have made optical fibers a very popular medium for large bandwidth communication applications. In particular, optical technology is being utilized more and more in broadband systems wherein communications between systems take place on high-speed optical channels. As this trend continues to gain more and more momentum, the need for efficient utilization of the precious real estate on circuit boards, racks/shelves, backplanes, distribution cabinets, etc., is becoming ever increasingly important. In order to fulfill expectations across the industry, opto-electronic modules and optic fiber devices need to continue to be made miniaturized or compact, thereby taking full advantage of the maturity of micro- and opto-electronic technologies for generating, transporting, managing and delivering broadband services to ever increasing bandwidth demands of end users at increasingly lower costs. Thus, the industry has placed an emphasis on optical components such as connectors and circuits, both simple and complex, that are of a specific size or geometry. However, miniaturizing and compacting is tempered by the requirements of transmission efficiency and organization of components, sub-systems and systems.
With the miniaturization of optical modules and optical fiber devices, the management of optical fiber congestion has become an issue at optical interfaces and connection distribution points. One solution is the use of multi-fiber ribbon in which a plurality of optical fibers are organized and contained side by side in a plastic ribbon.
However, in addition to straight connections, in some applications it is desirable to re-route the optical fibers in a multi-fiber ribbon and reconfigure the optical fibers in a new multi-fiber ribbon combination. Multifiber interconnection circuits are widely known and used in the field of optical fibers. A commonly known flexible optical fiber interconnection circuit includes a configuration of optical fibers sandwiched between a pair of flexible plastic sheets, such as Kapton, or a printed circuit board (PCB). Typically, at opposing edges of the pair of sheets are the circuit""s connection points for input and output. Generally, these circuits are connected at one end to another device for input, such as a laser array or another connector. The optical interconnection circuit reorganizes the light signals in a predetermined manner as it transports them across to the opposing end, typically connected to another connector or light transferring device. The input fibers and the output fibers can be either fusion spliced or mechanically spliced to the devices between which the interconnection circuit is to communicate. These interconnection circuits can take the shape of either a cross-connection circuit or a fan-out circuit.
In a typical cross-connection circuit, several separate groups of fibers are provided with input signals. Internal to the circuit, the groups of fibers can be separated and arranged to form new groupings, consisting of fibers from different input groups, to form output groups. This arrangement results in a reconfiguration of the fibers and, therefore, a reconfiguration of the light signal that was received by the interconnection circuit. The input groups can be made with ribbonized fibers or individual fibers. Where ribbonized fibers are used to provide the input for the cross-connection circuit, the fibers are separated within the structure of the circuit, reconfigured, and re-ribbonized into output groups. When individual fibers are used in the input groups, the individual fibers are separated from their input groups within the structure of the circuit and arranged to form new groups of fibers for output. These output groups can be ribbonized using ribbon connectors or another method of bonding fibers together at the output groups.
In a simple fan-out interconnection circuit, one group of fibers provides an input signal into the circuit, generally, as received from another device. The fibers are arranged in the circuit such as to separate the group, therefore separating the signal and providing multiple outputs. Similar to the cross-connection circuit, the fan-out circuit can be made using ribbonized fibers or individual fibers for the input.
In some applications it is desirable to manage a specified length of an optical fiber. Further, it is preferable to configure the fiber length so that it can be fitted in a low profile element such as a printed circuit card, or a module that can be used in a rack or shelf configuration of a communication system. It may also be desirable to control functional properties such as optical length of the fiber. This may require that the fiber length be arranged in a configuration that can be set on a temperature-controlled element, such as a hot or cold plate for which the temperature is set, controlled and maintained by a feedback mechanism.
Traditionally, such optical interconnection circuits have been manufactured by dedicated machinery or by hand. Production by dedicated machinery requires high initial investment costs and use of a machine that is either computerized or pneumatically controlled, with x-, y-, and z-, and possibly xcex8-, stages. These machines are large in size, bulky and expensive. Further, hand production is difficult to duplicate in high volume. Both production processes of hand or machines previously used are costly and require the use of highly skilled labor.
There continues to be strong market forces driving the development of fiber optic connection systems that take up less space and relieve congestion, while at the same time demanding that the increasing interconnection density and other unique requirements of the optical elements and modules be satisfied. Further, such optical elements or modules of an optical system should be capable of being manufactured and assembled easily and inexpensively.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.
The present invention provides an apparatus and method for making optical fiber circuits. Briefly described, the apparatus includes a mechanism that supplies or feeds an optical fiber, a rotary support for supporting an adhesive-coated substrate in such a way that the substrate is in contact with the optical fiber, and a linear tracking arm that routes the optical fiber in the shape of a planar spool on to the adhesive coated substrate. Further, the linear tracking arm may include a screw-thread mechanism to advance the position of the arm in either direction, and/or a fiber-pressing head attached to the arm that contacts the fiber, and fixes it while routing it on the adhesive-coated substrate.
The present invention can also be viewed as providing a method for making optical fiber circuits. In this regard, the method can be broadly summarized by the following steps: providing an optical fiber supply or feed mechanism, an adhesive coated substrate, a rotary support for the substrate, and a linear tracking arm having a fiber-routing head; mounting the substrate on the rotary support; and routing at least one layer of preferred length of the optical fiber drawn from the optical fiber supply mechanism and fixed into the tacky adhesive on the substrate in a desired shape such as a spiral, by using the rotary range of motion of the substrate support and the linear range of motion of the tracking arm to form a circuit. After completing the fiber routing, the fiber is severed, so that the routed fiber of the fiber circuit has a start-end and a finish-end. Further, the method may include the steps of removing the fiber circuit and substrate from the rotary support and linear tracking arm, and then applying a protective layer or coating to the substrate and the circuit. Additionally, the method may include the step of attaching the optical fiber spool to a temperature-controlled device so that its functional characteristics can be maintained by controlling the ambient temperature of the circuit.
Other systems, methods, features, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.